Level measurement device having electronics and antenna in one housing

ABSTRACT

Described is a radar filling level measuring device for non-contact measurement of a filling level of a filling matter in a vessel. A radar filling level measuring device including an electronics unit for generating transmission signals and for evaluating receiving signals reflected for a filling matter, an antenna unit connected to the electronics unit and adapted to radiate the transmission signals generated by the electronics unit in the direction of the filling matter and to receive the receiving signals reflected from the filling matter surface and to pass them on to the electronics unit, and a housing forming a cavity which is at least tight with respect to the atmosphere within the vessel and in which the electronics unit and antenna unit are acommodated. By this structure both the antenna unit and the electronics unit are protected in a technically simple and cheap way against aggressive ambient conditions and against chemical and mechanically abrasive aggression.

This application claims the benefit of provisional application60/371,990 filed Apr. 10, 2002.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention refers to a radar filling level measuring devicefor non-contact measurement of a filling level in a vessel or the likeby means of microwaves.

Such radar filling level devices are mainly used for continuous fillinglevel measurement as well as for limit level measurement of fillinglevels of any desired kind of filling matter in vessels, such asreservoirs. Filling level measuring devices of the above kind, however,might also be used for measuring the height of a liquid level of a fluidmedium such as a watercourse. In that case the device should be disposedabove the watercourse under a bridge or in any other way. In the presentcase, the term “vessel” should also embraces such environmentalconditions.

The filling matter can be present either in solid or in liquid form, ormay be a mixture of the two. The determination of the filling level isdone using radar signals, i.e. microwave signals, in particular veryshort microware pulses.

In short, the present device works as follows: signals (short microwavepulses or frequency modulated microwave signals) are generated in anelectronics unit and transmitted via an antenna unit in the direction ofthe surface of the filling matter to be measured. These signals arereflected on the filling matter surface and received by the antennaunit. The filling level can be determined using the delay of thesignals.

Description of the Related Art

Usually, radar filling level measuring devices are formed to be attachedin or on a vessel in such a way that the antenna itself extends throughan opening in the vessel cover. The housing containing the electronicsunit is arranged outside of the vessel as a matter of principle. Aspossibilities for attaching the radar filling level measuring devices,principally, flange and screw thread attachments are used. The flangeattachment is characterized by the radar filling level measurementdevices having a plate-like flange having through bores and having aconnecting section extending through its central opening connecting anelectronics unit of the radar filling level measuring device with thetransmitting and receiving antenna. Electronics unit here refers to thatportion of the filling level measuring device which generates at leastthe signals to be transmitted and radiated from the antenna unit in thedirection of the filling matter. The attachment flange may be placed ontop of a corresponding vessel flange of a vessel nozzle and screwed toit. In the screw thread attachment, the radar filling level measuringdevice often has a screw thread on a circumference thereof (externalscrew thread) which is to be screwed into a vessel opening having aninternal thread.

Both types of attachment have certain common features. Both with theflange attachment and with the screw thread attachment, the electronicsunit and the antenna unit are on different, opposing sides of a vesselwall. In both attachment types, the housing only serves to house theelectronics unit; the separate antenna unit is always connected to thishousing.

At the connecting point between the antenna unit and the housing,normally at least one connecting seam is formed having to be sealedusing suitable sealing means. Since this connecting or sealing seam issituated within the vessel, it is exposed to the vessel atmosphere andmust therefore be designed to be correspondingly resistant in order toensure vessel tightness. Furthermore, with the present attachment types,all antenna units often have the problem that they tend to be soiled,the soiling being caused by the filling matter present in the vesselsince they are always disposed on the inside of the vessel.

In fact, such radar filling level measuring devices have very often beenused in chemically aggressive environments or in the food industry.Thus, in order to protect the antenna units from soiling and possiblyagainst chemical or mechanically abrasive aggression, it is known in theprior art, to surround it with a solid layer of dielectric material(e.g. PP, PVDF, PTFE) or to only fill the funnel of an antenna hornelement with such a material. Such radar filling level measuring deviceshave been manufactured and marketed for example by VEGA Grieshaber KGunder the trade designation “Vegapuls 41” or “Vegapuls 43”.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of the present invention, an exemplaryembodiment of an inventive radar filling level measurement device fornon-contact measuring of a filling level of a filling matter in a vesselcomprises an electronics unit and an antenna unit. The electronics unitis for generating transmitting signals and for processing and, as thecase may be, for evaluating receiving signal reflected from the fillingmatter surface of the filling matter. The antenna unit is connected tothe electronics unit and adapted to radiate the transmitting signalsgenerated by the electronics unit and to receive the receiving signalsreflected from the filling matter surface and to pass them on to theelectronics unit. This exemplary embodiment of a radar filling levelmeasuring device according to the present invention further comprises ahousing completely enclosing both the electronics unit and the antennaunit. Preferably the housing consists of at least two housing portionsconnected to each other forming a cavity which is tight at least withrespect to the atmosphere in the vessel and where the electronics unitand the antenna unit are accommodated.

In other words, the radar filling level measuring device in an exemplaryembodiment of the present invention, for the first time comprises asingle housing for both the electronics unit and the antenna unit. Inanother exemplary embodiment of the invention, a housing portion of thehousing has an opening through which both the electronics unit and theantenna unit may be inserted and assembled. In operation, this openingis sealingly connected for example with a further housing portionserving as a cover, or with a further housing portion having a secondopening. The tight sealing of the housing against the environingatmosphere and/or the surrounding inside of the vessel, might be ensuredfor example by inseparably welding or gluing the two housing portionstogether. By the mentioned inseparable connecting means, any furthersealing elements may be mostly eliminated.

In an alternative exemplary embodiment of the present invention, thehousing portions may be connected by screw-thread connections or bymeans of screws. By the tight connection of the individual housingportions, a single unitary housing interior is created, in which boththe electronics unit and the antenna unit are mounted. Arranging boththe electronics unit and the antenna unit in this single unitaryinterior eliminates the need for costly cable and wire passage openingsbetween individual separate housing interior cavities. Using the radarfilling level measuring device of the present invention, such structuresare superfluous which in view of the sealing problems have always been adrawback in the past.

The interior of the radar filling level measuring device formed by thehousing could thus completely isolated from the surrounding atmosphere.The only connection between the interior of the radar filling levelmeasuring device and the surrounding atmosphere is by the necessarilyrequired power lead supplying the radar filling level measuring devicewith energy and ensuring signal exchange. Otherwise, the interior of theradar filling level measuring device is completely isolated against theatmosphere surrounding it and, in an exemplary embodiment of the presentinvention, is no longer accessible. Instead of the power lead, inanother exemplary embodiment of the present invention, the radar fillinglevel measuring device may also have a socket accessible from theoutside, into which the power lead may be plugged.

A radar filling level measuring device of the present invention maytherefore afford the advantage that both the antenna unit and theelectronics unit are arranged in the single interior space created bythe housing and are sealingly surrounded by the housing, in order toprotect these units against chemical and/or mechanically abrasiveaggression in aggressive environmental conditions. Further, simplemounting of the compact radar filling level measuring device is ensuredin any desired position of a vessel or in other measuring positions.

In an further exemplary embodiment of the present invention, the housingcomprises as few individual parts as possible in order to minimize thenumber of seams arising at each housing portion connection.

The housing of the radar filling level measuring device itself, inanother exemplary embodiment, is an integral plastics structure, whichis achieved by welding or gluing together the housing portions afterassembly of the electronics and antenna units. The radar filling levelmeasuring device is for example provided with suitable attachment meanson the side opposite from the radiating direction.

In another exemplary embodiment of the present invention, the radarfilling level measuring device has a horn-shaped antenna. Thishorn-shaped antenna may either be filled or unfilled. As the fillingmaterial, for example a dielectric material, such as PP, PVDF or PTFE,may be used. The radar filling level measuring device is provided withsuitable attachment means on the side opposite from the radiatingdirection.

According to the above-mentioned embodiment, the radar filling levelmeasuring device is attached in its entirety at the vessel cover bymeans of the attachment means. To do this, an opening in the vesselcover is no longer necessary. This can be particularly advantageous inapplications where such openings are undesirable or even impossible. Forexample in water tanks of solid reinforced concrete shells, suchopenings for the mounting of radar filling level measuring devices arevery disadvantageous or even impossible. In such a case, the overheadmounting of such a novel radar filling level measuring device isparticularly advantageous since it may very easily be attached to theinside of the vessel top by means of widely known dowels and using theabove mentioned attachment means.

The present embodiment might be particularly advantageous in that eachvessel of interest does not have to be specially prepared for mounting aradar filling level measuring device. Thus the vessels rather would notbe provided with nozzles or screw threads as has been previously thecase.

Apart from the possibility of mounting by means of dowels, the radarfilling level measuring device may of course also be attached on thevessel wall using any other suitable means, such as adhesives.

According to a further exemplary embodiment of the present invention,the radar filling level measuring device may be provided with a patchantenna including the required electronics units (RF module as well asdigital unit and power supply unit). The remaining structure of theradar filling level measuring device would otherwise be identical withthe above mentioned embodiment. The present exemplary embodiment mightbe particularly advantageous in that the radar filling level measuringdevice can be kept very small and flat in the radiating direction by theprovision of the radar filling level measuring device with a patchantenna. This might be particularly advantageous when there is verylittle space.

The mounting and attachment possibilities of the present embodiment mayidentical with those of the above explained exemplary embodiment of thepresent invention. Thus also the radar filling level measuring deviceaccording to this further exemplary embodiment may be doweled or gluedto the inside of the vessel, or it may be attached in an alreadyexisting vessel nozzle. Moreover, the radar filling level measuringdevice may also be provided with a screw thread on its outercircumference so that the radar filling level measuring device may bescrewed into a corresponding counter thread in a vessel.

The electronics unit generally comprises, amongst others, a transmissionand a receiving unit as well as, in an exemplary embodiment of thepresent invention, an evaluation unit. Thus, not all units need to bearranged in the interior of the housing of the radar filling levelmeasuring device. Of course, it is also possible, to arrange at leastone of the above units on the outside and to connect it with the radarfilling level measuring device using the connection cable, in order toachieve the required signal exchange and the energy supply.

For example, only the transmitting and receiving units may beaccommodated in interior of the housing of the radar filling levelmeasuring device. The evaluation unit may be remote thereof in aseparate housing outside of the vessel, such as in a control room. Inthat case, the received echo signal, which in an exemplary mode isconverted to an intermediate frequency range smaller than 1 MHz, will betransmitted via the connection cable from the receiving unit to theevaluation unit.

In a further exemplary embodiment of the present invention, a singlecentral evaluation unit may be connected using a plurality of cableswith a multitude of transmitting and receiving units, and maysequentially evaluate the receiving signals of each unit and therefore amultitude of filling levels of different vessels or vessel sections.

If the evaluation unit is accommodated in combination with thetransmitting and receiving units within the housing interior of theradar filling level measuring device of the present invention, theconnecting cable contains leads for energy supply of the sensor as wellas for transmitting the measuring values and perhaps further informationand operating parameters between the sensor and a higher level processcontrol system.

In an other exemplary embodiment of the present invention, theconnecting cable contains only two leads carrying the energy supply aswell as the information exchange. Such systems have been known in such aform that the measuring value is transmitted as a value superimposed onthe supply currant by the sensor (4 . . . 20 mA-two-wire sensor).

In a further variant, the information is modulated in digital form onthe power supply line. Examples of such systems are Profibus-PA sensorsand sensors according to the Fieldbus Foundation standard.

An advantage of the above-identified exemplary embodiments of thepresent invention, as has been explained, may be that for the mountingin the vessel, no “flange” or “screw thread” approach need necessarilybe employed. Thanks to this novel housing, the radar filling levelmeasuring devices may be positioned at any desired measuring positionswithout the need for additional auxiliary structures or extensivemounting expense. A adaptation of the radar filling level measuringdevice to an already present means such as a flange or a screw thread istherefore eliminated.

Alternatively to the mounting approaches already described, however, another exemplary embodiment of the present invention may also be used formounting it in already existing vessel nozzle openings. In that case,the radar filling level measuring device is inserted from the top intothe existing vessel nozzle opening and connected to the vessel nozzleflange by means of the attachment means opposite to the radiationdirection. In this exemplary embodiment suitable for mounting inexisting vessel openings, it is also advantageous for the connectionseam of the housing portions to be arranged outside of the vesselatmosphere. This is to achieve that the tightness of the vesselatmosphere with respect to the atmosphere surrounding the vessel is onlydependent on the mounting of the radar filling level measuring device inthe vessel opening, the tightness of which can usually be easilycontrolled. The tightness seams critical in prior approaches andresponsible for vessel tightness between the antenna unit and thehousing, are thus completely eliminated. Sealing of the vesselatmosphere within the radar filling level measuring device is no longernecessary, leading to a simplified construction.

The manufacture of radar filling level measuring devices of the presentinvention may be cheaper compared to the known more expensivelystructured sensor housings, since due to the simple form of thehousings, the design and construction cost may be minimized.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For further explanation and to more fully understand the presentinvention, a number of exemplary embodiments of the present inventionwill be described in more detail with reference to the accompanyingdrawings, in which:

FIG. 1 is a vertical sectional view of a radar filling level measuringdevice according to the invention having a filled horn antenna andmounted at a vessel cover;

FIG. 2 is a vertical sectional view of a radar filling level measuringdevice according to the invention having a filled horn antenna andattached in a vessel nozzle;

FIG. 3 is a vertical sectional view of a radar filling level measuringdevice of the present invention having a patch antenna;

FIG. 4 shows a screw-type radar filling level measuring device of thepresent invention having an outer contour; and

FIG. 5 is a vertical sectional view of a radar filling level measuringdevice of the present invention having three housing portions.

Like numerals have been used to designate like elements throughout inthe drawings.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, a vertical sectional view of a radar fillinglevel measuring device 1 attached to a vessel cover 7 is shown. Thevessel cover 7 is of re-enforced concrete. The radar filling levelmeasuring device 1, consisting of a housing pot 2 and a housing cover 3,is of plastics material, preferably PP or PTFE. The housing pot 2 iscylindrical in form and is provided with a housing flange 5 round itscircumference on its side opposite from the radiating direction A andextending around its entire circumference. In the direction of theradiating direction A, the cylinder ends in a solid circular taperhaving a main axis coinciding with the radiating direction A. On theside opposite to the radiating direction A, the housing pot 2, on theinside of its side wall, has an annular recess 12. The circular,disk-like housing cover 3 has its diameter matched to the circularcavity formed by the recess 12.

Before the housing pot 2 is closed by the housing cover 3, theelectronics unit 4 and an antenna horn 6 a (only schematically shown)are mounted in the interor 11 of the radar filling level measuringdevice 1. A connecting cable 10 is passed through a sealed openingarranged in the housing flange 5 into the interior of the filling levelmeasuring device 1 (not shown). As soon as these parts have beeninserted and mounted, the housing pot 2 is closed by the housing cover3. In order to seal the interior 11 of the filling level measuringdevice 1 against the ambient atmosphere, the seam 17 arising between thehousing pot 2 and housing cover 3 will be filled with an adhesive,whereby the housing cover 3 is sealingly connected to the housing pot 2.By this tight adhesive bonding the integrity of the housing of thefilling level measuring device 1 as well as the tight sealing of thehousing interior 11 with respect to the ambient atmosphere surroundingthe filling level measuring device 1 is ensured. Alternatively to theadhesive bonding, the housing cover 3 may also be permanently bonded thehousing pot 2 by welding.

Instead of the permanent bonding, it is also possible to screw the cover3 by means of a screw thread or to connect the cover 3 on the housingpot 2 by means of screws. For the latter approach, the use of anadditional gasket is necessary.

The filling level measuring device 1 is finally attached to there-enforced concrete vessel top wall 7. To do this, a multitude ofsuitable attachment means may be used. Dowels, arranged in the axes B,are particularly suitable for this. A different, very advantageous andeasily manageable attachment approach of the filling level measuringdevice 1 to the vessel top wall 7, consists in gluing the housing cover3 to the vessel top wall 7. Suitable adhesives are in particularhigh-performance adhesives, such as epoxy resins. A third approach forthe attachment consists in the use of a jointing flange which is slippedover the housing as a separate annular part and is attached to thevessel top wall.

FIG. 2 shows a sectional view of a filling level measuring device 1attached in a vessel nozzle 8 having a flange 9. The filling levelmeasuring device 1 is no different from the one in FIG. 1. The fillinglevel measuring device 1 is attached in the vessel nozzle 8 via theannular vessel flange 9 on the housing flange 5, wherein the flange 5 ofthe filling level measuring device 1 is adjacent to the flange 9 of thevessel. Suitably screws in the axes B are used here as an attachmentmeans. Also conceivable, of course, would be, analogous to theattachment type used in FIG. 1, to glue together the flanges 5 and 9 attheir common seam, or alternatively, the use of a jointing flange.

In FIG. 3, a vertical sectional view of a filling level measuring device1 having a patch antenna is shown. The filling level measuring device 1,consisting of a housing pot 2 and the housing cover 3, is made ofplastics material. The housing pot 2 has a flat cylindrical form and isprovided with a housing flange extending around its periphery andextending round the entire circumference of the housing pot 2. In thedirection of radiating direction A, the cylinder ends in a solidcircular taper, whose main axis coincides with the radiating directionA. On its side opposite the radiating direction A, the housing pot 2 hasan annular recess 12 on the inside of its side wall. The circular,disk-like housing cover 3 has its diameter matched to the circularcavity formed by the recess 12.

Before the housing pot 2 is closed by the housing cover 3, theelectronics unit 4 (only schematically shown) and a patch antenna 6 bare mounted in the interor 11 of the radar filling level measuringdevice 1. The connecting cable 10 is passed through a sealed openingarranged in the housing flange 5 into the interior of the radar fillinglevel measuring device 1 (not shown). As soon as these parts have beeninserted and mounted, the housing pot 2 is closed by the housing cover3. In order to seal the interior 11 of the filling level measuringdevice 1 against the ambient atmosphere, the seam 17 arising between thehousing pot 2 and housing cover 3 will be filled with an adhesive,whereby the housing cover 3 is sealingly connected to the housing pot 2.By this tight adhesive bonding the integrity of the housing of thefilling level measuring device 1 as well as the tight sealing of thehousing interior 11 with respect to the ambient atmosphere surroundingthe filling level measuring device is ensured. Alternatively to theadhesive bonding, the housing cover 3 may also be permanently bonded thehousing pot 2 by welding.

Instead of the permanent bonding, it is also possible to screw the cover3 by means of a screw thread or to connect the cover 3 on the housingpot 2 by means of screws. For the latter approach, the use of anadditional gasket is necessary.

FIG. 4 shows a further exemplary embodiment of a radar filling levelmeasuring device of the present invention screwed into a vessel nozzle 8having an internal thread 15. The housing pot 2 is provided with anangular outside contour 13 and an external thread 14. The radar fillinglevel measuring device 1 can be screwed using a tool using said outsidecontour 13, preferably in the form of a hexagon, into the internalthread 15 of the vessel nozzle 8. The housing portions 2 and 3 of theradar filling level measuring device 1 in this embodiment, as againstprevious embodiments, have a different form which, however, does nothave any effect on the principal structure of the radar filling levelmeasuring device 1, therefore not deviating from the previousembodiments. Thus the radar filling level measuring device 1 of thepresent embodiment, in its single interior 11 also has a horn antenna 6a and an electronics unit 4. Instead of the horn antenna 6 a, in thisembodiment, one or more patches can of course also be used as theantenna unit.

Of particular advantage in the embodiment shown in FIG. 4 is theavoidance of a connection or sealing seam of the housing within thevessel. The connection between the housing pot 2 and the housing cover 3lies outside of the vessel atmosphere and may be achieved in the sameway as shown in FIG. 1, 2 or 3. The tightness of the vessel with respectto the ambience, however, is not affected by a connection seam of twostructural parts of the radar filling level measuring device.

Unlike the view shown in FIG. 4, the present embodiment may also beattached on a vessel flange according to the previous embodiments usingscrews arranged in the axes B. The present embodiment is also suited forthe previously described mounting on the top wall, wherein the radarfilling level measuring device 1 is either glued or screwed to the cover3.

FIG. 5 shows a sectional view of the principal structure of a housing ofa further exemplary embodiment of a radar filling level measuring deviceof the present invention, consisting of three housing parts 2, 3 and 16bonded at the associated seams 17 or 18 using suitable means. Theremaining structure of the embodiment shown in FIG. 5 is identical tothe structure of the embodiment shown in FIG. 3. The difference of theembodiment shown in FIG. 5 as against the embodiment according to FIG. 3is only that the housing of the radar filling level measuring device isassembled from three individual housing parts 2, 3 and 16. Of course,the housing can also be assembled from any number of housing parts. Thiscan be particularly advantageous when for example the housing capacityhas to be enlarged.

Changes can of course be made on the embodiments of the presentinvention without departing from the scope of the invention. Theembodiments mentioned only serve to more fully explain the invention andmay in no way be construed as restricting the scope of protection of thepresent invention.

1. A radar filling level measuring device for non-contact measurement ofa filling level of a filling matter in a vessel, comprising: anelectronics unit generating transmitting signals and processingreceiving signals reflected from a filling matter surface of the fillingmatter; an antenna unit connected to the electronics unit and adapted toradiate the transmission signals generated by the electronics unit in adirection of the fllling matter and to receive the receiving signalsreflected from the filling matter surface and to pass them on to theelectronics unit; and a housing having a cavity, the cavity being atleast tight with respect to an atmosphere in the vessel, the electronicsunit and the antenna unit being situated in the cavity.
 2. The radarfilling level measuring device according to claim 1, wherein the housingconsists of at least two housing portions connected to each other. 3.The radar filling level measuring device according to claim 2, whereinan area in which the at least two housing portions are connected to eachother is adapted to be outside of the vessel when the radar fillinglevel measuring device is mounted at the vessel.
 4. The radar fillinglevel measuring device according to claim 2, wherein at least one of theat least two housing portions has at least one insertion opening formedso that at least one unit of a group of units is insertable and theother of the at least two housing portions is adapted for closing the atleast one insertion opening, the group of units consisting of theelectronics unit and the antenna unit.
 5. The radar filling levelmeasuring device according to claim 2, wherein each of the at least twohousing portions encloses a cavity which is open at least to one side,the at least two housing portions being joined to each other at theiropen sides.
 6. The radar filling level measuring device according toclaim 5, wherein between the at least two housing portions, eachenclosing a unilaterally open cavity, at least one further housingportion is inserted to enlarge the cavity formed by the at least twohousing portions together.
 7. The radar filling level measuring deviceaccording to claim 2, wherein the at least two housing portions arejoined using at least one screw connection.
 8. The radar filling levelmeasuring device according to claim 2, wherein the at least two housingis formed having an attachment arrangement for mounting the radarfilling level measuring device.
 9. The radar filling level measuringdevice according to claim 8, wherein each of the at least two housingshas through-openings for attachment screws of the attachmentarrangement.
 10. The radar filling level measuring device according toclaim 8, wherein each of the at least two housings has at least oneattachment surface for positioning the radar filling level measuringdevice adjacent to one of a top wall and a side wall of the vessel asthe attachment arrangement.
 11. The radar filling level measuring deviceaccording to claim 8, wherein each of the at least two housings has aflange on the outside serving as the attachment arrangement.
 12. Theradar filling level measuring device according to one of claim 2,wherein each of the at least two housings has at least one attachmentsurface for positioning the radar filling level measuring deviceadjacent to one of a top wall and a side wall of the vessel andthrough-openings for attachment screws as an attachment arrangement formounting the radar filling level measuring device.
 13. The radar fillinglevel measuring device according to claim 2, wherein each of the atleast two housings has a screw thread on an outside that may be screwedinto a vessel opening having an internal thread as an attachmentarrangement for mounting the radar filling level measuring device. 14.The radar filling level measuring device according to claim 13, whereinthe at least two housings has an outside contour serving to provideengagement using a tool in addition to the outside screw thread.
 15. Theradar filling level measuring device according to claim 14, wherein theoutside contour has a hexagonal shape to be engaged by a spanner. 16.The radar filling level measuring device according to claim 2, whereinat least one of the at least two housing portions consists of a plasticsmaterial.
 17. The radar filling level measuring device according toclaim 16, wherein the plastics material is one of PP and PTFE.
 18. Theradar filling level measuring device according to claim 1, wherein theat least two housing portions are welded together.
 19. The radar fillinglevel measuring device according to one of claim 1, wherein the at leasttwo housing portions are glued together.
 20. The radar filling levelmeasuring device according to claim 1, wherein the housing has aconnection by which the electronics unit is supplied with energy andthrough which a communication is achievable with the radar filling levelmeasuring device.
 21. The radar filling level measuring device accordingto claim 1, wherein the antenna unit includes one of a horn antenna anda patch antenna.
 22. A radar filling level measuring device fornon-contact measurement of a filling level of a filling matter in avessel, comprising: a circuit generating transmitting signals andprocessing receiving signals reflected from a filling matter surface ofthe filling matter; an antenna assembly connected to the circuit andadapted to radiate the transmission signals generated by the circuit ina direction of the filling matter and to receive the receiving signalsreflected from the filling matter surface and to pass them on to thecircuit; and a housing consisting of at least two housing portionstightly connected to each other at a plurality of connection areas andforming a cavity which is tight with respect to the atmosphere in thevessel; an attachment arrangement attaching the radar filling levelmeasuring device at the vessel, wherein the attachment arrangement isarranged in the housing so that, viewed in the direction of radiation ofthe transmission signals, a first portion of the housing is in front ofthe attachment arrangement and a second portion of the housing is behindthe attachment arrangement, wherein the circuit and the antenna assemblyare accommodated in the cavity, and wherein the connection areas are inthe first portion of the housing.
 23. The radar filling level measuringdevice according to claim 22, wherein the attachment arrangementincludes an attachment flange.
 24. The radar filling level measuringdevice according to claim 22, wherein the attachment arrangementincludes a screw thread formed as an external thread on the housing andwhich may be screwed into a screw thread in a vessel opening.